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Syarifa, A.

Publications and source records attributed to Syarifa, A..

2 recordsLinked to original sources
bioRxiv2026

Karyotypic evolution in a diverse primate clade and the role of chromosomal fissions as barriers to gene flow

The classical model of chromosomal speciation is based on the observation that divergent species often differ in chromosome numbers and that heterokaryotypic hybrids show reduced fitness. Furthermore, positive correlations between the rates of karyotype evolution and speciation have been established in several groups of organisms. Yet, the mechanisms that make some lineages more prone to chromosomal fissions and fusions than others, and the causal role of such karyotype changes in speciation, are poorly understood. Here, we focus on the taxonomically and karyotypically diverse group of African monkeys, the guenons (tribe Cercopithecini), consisting of ~35 species with diploid chromosome numbers ranging from 48 to 72. We generated de novo genome assemblies for eight species with different karyotypes, and incorporated publicly available genomes from additionally three guenon species. Using the rhesus macaque as an outgroup, we identified 28 independent chromosomal fissions and 4 fusions in guenons. In line with previous cytogenetic studies, repeat composition around chromosomal breakpoints suggested that most fissions were non-centromeric, requiring the evolution of a new centromere in at least one of the fission products. In contrast to the expectation under strong underdominance, we found a paraphyletic distribution of several chromosomal fissions. Some of these phylogenetically discordant events could have resulted from interspecific hybridization, whereas others are more likely caused by incomplete lineage sorting, suggesting that fissioned and non-fissioned homologs segregated in ancestral guenon lineages for millions of years. Nevertheless, we find evidence for reduced introgression on rearranged chromosomes in an ancient cross-karyotypic gene flow event between Cercopithecus cephus and C. pogonias. Although this suggests that chromosomal fissions may have constituted barriers to gene flow in the guenon evolution, the signal was inconclusive or absent in two other investigated gene flow events. This study provides important first insights into the remarkable karyotypic diversification of guenons, and its role in generating reproductive barriers.

evolutionary biology↗
bioRxiv2026

Cultural transmission and genomic co-divergence in the willow tit across the Palearctic

Cultural transmission of mating behaviour can both promote and constrain genetic divergence, yet its long-term population-genetic consequences remain unclear. In songbirds, learned song can generate behavioural isolation, but its potential to shape genome-wide differentiation at continental scales is rarely assessed. Willow tits provide a compelling system, as three culturally transmitted song types are largely allopatric across the Palearctic, while northern populations exhibit mixed repertoires. Here, we combined a chromosome-level reference genome, whole-genome resequencing of 88 willow tits (Poecile montanus) spanning all 14 subspecies, and palaeodistribution modelling to reconstruct the species evolutionary history across the Palearctic. Phylogenetic and demographic analyses indicate an origin in Asia during the Late Pliocene to Early Pleistocene, followed by expansions that yielded three deeply diverged genomic lineages in the Asian, Central European, and Northern Palearctic regions. The boundaries of these lineages coincide with major song-type divisions. Tests of historical allele sharing show that gene flow occurred preferentially among lineages that share the same or similar song types, even after accounting for geography, consistent with learned song contributing to prezygotic isolation. Peripheral, song-monotypic populations exhibit signatures of repeated bottlenecks associated with glacial isolation, whereas large northern populations retained broader song repertoires and signals of long-term connectivity. These results provide genome-wide continental evidence that culturally transmitted song mirrors and likely reinforces genomic structure through time in a widespread passerine bird.

evolutionary biology↗